Due to
machine traffic, soils react in different ways to compaction. The Eidgenössische
Forschungsanstalt WSL (Switzerland) has classified ruts on trails according to
three types:
With type
1, we can see small ruts that witness to some degree of compaction, but there
are no ridges on the sides. This type of rut is very stable and allows for
further passages.
With type
2, ridges appear at the sides of the ruts: they derive from the soil being
pushed aside by the wheel. This type is stable, too, but the ridges are a
warning that we are close to the limit and must be very careful.
With type
3, new ridges appear that derive from semi-liquid soil flowing out of the ruts.
This is a clear indicator that traffic must be stopped.
